Central sensitization is a condition where the nervous system remains in a persistent state of high reactivity. This state can amplify pain and trigger other unexplained symptoms. Over time, the nervous system becomes more efficient at sending pain signals, meaning less stimulus is needed to produce pain. The Central Sensitization Inventory (CSI) is a questionnaire designed to identify symptoms associated with this condition and serves as a screening tool for clinicians to understand a patient’s symptom profile.
What Is the Central Sensitization Inventory?
The Central Sensitization Inventory is a self-report questionnaire that measures symptoms related to central sensitization (CS). It is divided into two parts, Part A and Part B. Part A is the primary component and consists of 25 questions that ask individuals to rate the frequency of health symptoms. These questions cover issues such as muscle stiffness, sleep problems, headaches, and sensitivity to light or smells.
Part B of the inventory is not scored but provides clinical context. This section asks whether an individual has been diagnosed with specific conditions often associated with central sensitization. These can include fibromyalgia, irritable bowel syndrome, chronic fatigue syndrome, anxiety, and depression. This information helps a healthcare provider understand the patient’s medical background.
Due to copyright protections, a PDF of the inventory cannot be provided here. However, legitimate copies of the CSI are often available from its developers, the PRIDE Research Foundation, and can sometimes be found in the appendices of published research articles that have used the inventory.
Scoring the Inventory
Scoring the inventory focuses entirely on Part A, as Part B is for informational purposes and does not contribute to the final score. Each of the 25 questions in Part A is rated on a 5-point scale that reflects the frequency of the symptom.
The scale assigns points as follows: “Never” is 0 points, “Rarely” is 1 point, “Sometimes” is 2 points, “Often” is 3 points, and “Always” is 4 points. To calculate the total score, you sum the numerical values from each of the 25 responses. The resulting score will fall between 0 and a maximum of 100.
This final number provides a quantitative measure of a person’s symptoms and is used to screen for central sensitization. The simple scoring allows for quick assessment in a clinical setting.
Interpreting the Score
The total score from Part A of the Central Sensitization Inventory offers insight into the likelihood that central sensitization is contributing to a person’s symptoms. A cutoff score of 40 is widely used as a clinical indicator. A total score of 40 or greater suggests that the symptoms reported are likely related to central sensitization and that the individual may have a central sensitivity syndrome (CSS).
While 40 is the most common threshold, some research has proposed other scoring ranges to classify the severity of symptoms. These classifications can help a clinician better understand the patient’s experience and tailor their approach. The levels are categorized as:
- Subclinical (0-29)
- Mild (30-39)
- Moderate (40-49)
- Severe (50-59)
- Extreme (60-100)
The CSI is a screening tool, not a diagnostic instrument. A high score does not confirm a diagnosis of central sensitization or any related condition. The results must be interpreted by a qualified healthcare professional. A clinician will use the score as one piece of a comprehensive evaluation, considering it alongside a physical examination, medical history, and other relevant clinical findings to make an accurate diagnosis.